Virtualization/Emulation

Overview

The topic of virtualization and emulation can get quite involved and this will not be a full treatment of the subject. We will focus on the positives and negatives of using virtualization in a post production environment.

Virtualization refers to the abstraction of computing resources. That is placing a layer in between the operating system and the hardware on which that operating system runs.

For the purpose of running software that isn't available on linux we're most interested in Hypervisors.

Another reason for considering virtualization is failover. Some hypervisors support shifting a running virtual machine from one physical machine to another. This allows you to ensure critical infrastructure continues running, such as your renderfarm manager server failing over without the renderfarm software needing to support it.

Performance

The performance of virtualized machines can be very close to running an operating system natively when used with a hypervisor that supports Hardware-assisted Virtualization. Graphics hardware acceleration won't be available with windows as a guest OS as this requires Paravirtualized drivers. If you are using a *nix guest and would like hardware acceleration of opengl then take a look at VGML. The really brave of you may even look at porting the guest driver to windows, which would provide opengl acceleration on a windows guest.

Ease of Use

The user will need to use a virtual machine manager to access applications under their virtual machine.

They will also most likely need to use it in a mode where it grabs their input devices adding extra complexity to switching between applications running on their host OS.

Depending on which option you choose you should be able to direct a USB wacom to be used by the guest OS, though this will likely involve disabling it in your host OS. Please let me know if you try this and what the results were.

Ease of Configuration

The complexity of setting up a virtual machine will vary depending on the software you've chosen and your host OS. Some distributions come with a virtual machine manager installed by default, in which case the bulk of the work will be setting up the guest operating system. This will be performed almost identically to installation of that operating system on a physical machine.

Flexibility

Virtualization provides great flexibility with regards to your choice of guest operating system as well as your overall systems architecture (in assisting for failover and redundancy). It also provides the possibility of assisting with security by having a virtual machine for a particular server task, which in turn makes your pipeline more scalable as when demand increases too much you can split that virtual machine off onto a more powerful or dedicated server.

Particularly when providing this to artists though it does come with a caveat of exposing your network to any security vulnerabilities of your guest OS. If you're using windows as the guest, it could be a good idea to use NLite to strip out as much as possible (particularly IE) and limit this machine so it will only run the minimum applications required. Configuring the machine so it does not have access to your network, but just the home directory of the user running it will also help minimize it's potential for damage. You may also find it beneficial, regardless of OS, to make this image ready only once it is configured. This way each time it's used to will be booting into a clean state.

Cost

Many virtualization solutions are licensed under a free software license, which means you will be able to obtain a hypervisor at no cost if you wish. Though if your guest operating system is proprietary you will still need to purchase a license for this. I am not familiar with the situation regarding operating system licenses and floating virtual machines so I'd advice you consult a lawyer to ensure you license correctly in this scenario.